1. Field of the Invention
The invention relates to a composition for consolidating moulded articles and geological formations from porous or particulate materials.
2. Discussion of Background Information
The preparation of composite materials from particulate systems with suitable binding agents is especially difficult, if the composite materials should not lose its porosity considerably compared to a binder-free packing. Thus, porous composites can be prepared e.g. with organic polymeric binding agents, but it becomes apparent that it is hardly possible to maintain the original porosity. It is possible to prepare porous systems by a reduced use of binding agent, however, such composites are not suitable for many applications, in particular at higher temperatures and in the environment of organic liquids due to the property of the organic polymers to swell up or become dissolved in the presence of organic solvents.
Although the use of purely inorganic binding agents, which are available e.g. by the sol-gel process, results in binding with which a corresponding porosity is maintained in the moulded article, the bonded system is very brittle, flawy and not sufficiently resistant to mechanical loading such as shear loading or intense pressure load.
A special field of consolidation of particulate materials is crude oil recovery, in which bore-holes are often driven in non-consolidated geological formations. In particular in the case of offshore exploitation, there are sand containing geological formations that have to be consolidated to avoid penetration of sand and other rock particles into the bore-hole, which is connected with damage of the conveying devices and with contamination of the crude oil recovered. Usually, a three-stage process is used for consolidation of such sand fields. At first, a synthetic resin binding agent is injected through a probe, after which it is cured by injection of an activation system. In a third step a system for controlling permeability and for pushing out a surplus of resin binding agent is injected.
It was an object of the invention to provide a consolidation agent for moulded articles and geological formations from porous or particulate materials, e.g. sand containing geological formations, achieving a good binding strength with sufficient flexibility and a porosity essentially not reduced and maintaining its binding properties also in the case of soiled particulate materials, in particular also in the case of not degreased or oil containing particles.